Cartoning apparatus normally contain a magazine for receiving a supply of flat folded carton blanks and apparatus for ejecting those carton blanks from the magazine and erecting them into a generally rectangular tubular form. The cartoner typically includes a pair of endless chains, one carrying leading transport lugs and the other carrying trailing transport lugs. In such apparatus, a carton is erected and captured between the leading and trailing transport lugs. The carton is then held between these lugs as it passes through a filling station.
As the carton passes through the filling station, a barrel loader thrusts product into the carton, and as it passes through a gluing and flap closing apparatus, the carton is sealed. However, if a carton as it is transported through the sealing stages is not square, the flaps are misaligned on the resulting package making it an unsightly or unacceptable package.
In typical applications, cartoner require frequent changeovers for running different sizes of cartons. In the changeover, mechanics use wrenches to loosen parts, slip the parts relative to one another and retighten the parts to fix them in that position. For example, the chain carrying the leading lug is physically shifted with respect to the chain carrying the trailing lugs to accommodate cartons of greater or lesser length. In this case, length refers to the dimension in the direction of machine movement, i.e., the carton width taken across the "face" or front panel of a carton.
One approach for automatically changing a carton over from one size to another is disclosed in U.S. Pat. No. 4,718,540 of Greenwell, which is incorporated herein in its entirety by reference. That patent discloses a horizontal cartoner having a main drive, an element, such as transport lugs and product bucket elements that are adjustable to accommodate different sizes of canons. The patent also discloses automatic means for varying the position of those elements automatically using the power of the main drive to accomplish the adjustment while the machine is running. For example, if the machine is set to run a particular product and carton size, it is possible that the delivered carton may be dimensionally different from a previous run and do not handle as well. However, adjusting the transport lugs with respect to each other while the machine is running enables an operator to make adjustments while observing the operation on the machine. In essence, the phase adjusting system effects the linear adjustment of the center chain with respect to the outside chains, thereby adjusting the spacing between the leading and trailing transport lugs to accommodate different sizes of cartons.
The concept of a mechanism for squaring a carton is addressed in U.S. Pat. No. 4,571,236 of Adams. As disclosed therein, all of the leading lugs are inclined rearwardly at a slight angle from a vertical attitude. Thus, the rearwardly incline leading lugs will engage the upper leading corner of the carton. The center chain carrying the leading lugs is then adjusted longitudinally with respect to the chains carrying the trailing lugs so that the spacing of the lugs can be altered into the cartons carried between the lugs are maintained in a squared attitude through the processing.
It has now been recognized that there may be a significant demand for an improved cartoner which maintains parallelism when the apparatus is moving along a non-linear path. It is also desirable that the apparatus maintains the squareness of a container as it moves through the filling station and along a non-linear path so that the filling station may be located in various positions along the path.
It is presently believed that an improved cartoner according to the present invention will provide the aforementioned desirable features. It is also believed that an improved cartoner in accordance with the present invention provides means permitting individual or simultaneous adjustment of a fixture or locational device and means for the parallel adjustment for two or more surfaces. In addition, the approach according to the present invention provides for manual or power driven adjustment and an opportunity for position monitoring during the operation of the cartoner.
In addition, an improved cartoner in accordance with the present invention maintains parallelism when the cartoner is dynamically loaded and isolates the driving mechanism from external bending moments. The cartoner maintains parallelism throughout the entire process even in those cases where a drive chain has become stretched or worn. The apparatus also allows variation in cord length versus are length of the chain to be controlled and compensated for as illustrated hereinafter. In addition, such cartoners can be economically manufactured and marketed in a competitive market, readily installed and maintained and are durable.